Sound reproducing system



May 11, 1948. o. R. LAWRENCE 2,441,425

SOUND REPRODUCING SYSTEM Filed Sept. 13, 1946 2 Shets-Sheetl Qvwem Iowfirms iJdZZIZI/(f May 11, 1948. o. R. LAWRENCE 2,441,425

SOUND REPRODUCING SYSTEM Filed Sept. 13, 1946 2 Sheets-Sheet 2 aidsZZ-Za 2477297863 Patented May 11, 1948 UNITED STATES PATENT OFFICE2,441,425 sounn REPRODUCING SYSTEM Oras R. Lawrence, Pleasantville, N.J.

Application September 13, 1946, Serial No. 696,766

1 Claims. My invention relates to new and useful improvements in soundreproducing systems and has for an object to provide a sound reproducingsystem that is especially adaptable for use with electric organs, butmay also be used with other musical instruments of a certain type thatsupply the necessary audio-frequency notes.

One of the objects of the invention is to providea sound reproducingsystem to be used with an electric organ, that will faithfully reproducethe sound and also provide a pleasing tremolo effect not only for thenotes in the upper frequency but also for the notes in the middle andlower or bass frequencies.

Still another object of the invention is to provide a system wherein thesound or tones from two dynamic cone speakers, as well as what is knownas a dynamic driver type speaker, are directed upward through areverberating chamber, and the sound then deflected outwardly by a rotorsound deflector in a lateral direction.

Still another object of the invention is to provide an improved meansfor creating not only a tremolo effect for the notes from an electricorgan, but to cause a reverberation of the music to simulate the tonesfrom a pipe organ, and to slightly reduce the reverberation of the highfrequency notes but at the same time increase their brilliancy.

Still another object of the invention is to provide a cabinet in whichthere is a reverberating metal chamber in which the sound, or in otherwords, the music, is directed from two dynamic cone speakers as well asa speaker of the high frequency type.

Still another object of the invention is to provide a reverberatingchamber with its speakers, while at the top of the chamber there ismounted a rotor in the form of a sound deflector to create a noveltremolo effect; while behind the dynamic speakers in turn there is abaflie board with the necessary openings and a second or lower rotatingsound deflector, so that a tremolo eifect can be given to sound or musicthat is issued from the back of the dynamic cone speakers but has notpassed up in to the reverberating chamber.

Still another object of the invention is to produce a sound reproducingsystem that will lend brilliance to the tones and over-tones that issuefrom the sound cabinet, and will reproduce with high fidelity the notesin the high, low and lower frequencies; and will also produce a tremoloeffect and a reverberation that is not possible, so far as I am aware,with other sound reproducing cabinets.

Still another object of the invention is to provide a simple mechanismfor carrying out the re-' production, which consists primarily of acabinet with two amplifying cone speakers, a dynamic driver typespeaker, a reverberating chamber and two rotors, through which the musicpasses, so that not only are the tonal qualities of the instrumentplayed improved and faithfully reproduced, but the music or notes may beheard equally as well anywhere within a 360 radius.

With these and other objects in view the invention consists in certainnew and novel arrangements and combination of parts as will behereinafter more fully described and pointed out in the claims.

Referring now to the drawings, showing a preferred embodiment,

Fig. 1 is a vertical, sectional view of a cabinet with my improvedmechanism therein,

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1,

Fig. 3 is an enlarged, fragmentary, detailed view, showing the upperrotor and the means for revolving the same,

Fig. 4 is an enlarged, fragmentary, vertical, sectional view, showingthe manner of mounting the rotor sound deflectors, and

Fig, 5 is a fragmentary, sectional view taken on line 55 of Fig. 4.

Referring now to the several views, and for the moment, to Fig. 1, thereis shown a cabinet I, which is provided with lattice or grille work 2about its upper end so that the sound may pass therethrough, while nearthe bottom of the cabinet I is a baffie board 3, which is providedcentrally with the openings 4, and under these openings 4 is positionedthe bottom rotor sound deflector, as will later be described.

Likewise, just beneath the lattice work 2, extending across the cabinetI, there is a supporting board 5, and a lower supporting board 6, whichis slightly spaced above the baffle board 3. Securely mounted betweenthese boards 5 and 6 is a metal housing I that forms what I term thereverberating chamber 8. This housing 1 might be described as conical inshape through its greater dimension and having flatted sides 9 (see Fig.2) x The apex I6 is nearly circular in top plan while the bottom II hasparallel sides 9, and rounded semi-circular ends II.

This housing 1 is open at its top and at its bottom, as in the bottomare to be fitted two speakers that will be mentioned shortly, while overthe top is mounted an upper rotor sound deflector also to be mentionedshortly.

This housing 1, that forms the reverberating chamber 8, is formed ofcopper or brass, or even tin; and is supported to reverberate from thesound that is admitted to the chamber 8, to thus more closely simulatethe hollowness or timbre of the reverberating pipes of a pipe organ.

It will be noticed that there is a flange I2 for conveniently securingthe upper part of the housing 1 to the board 5, and a flange l3 at thelower end of the housing 1 to likewise secure this metal housing 1 tothe two boards 5 and 6 heretofore mentioned.

It may also be noticed, from Fig. l, I cut an opening H3 in the side ofand near the bottom of the housing i, so that there can be conven ientlymounted a dynamic driver type speaker l5 with its horn it that extendsupwardly in the reverberating chamber 8. It will be noticed that thehorn i6 is of the long, narrow type so that the high audio-frequencynotes are faithfully reproduced.

It will also be noticed that the sound passing through the horn I6 isled into the upper part of the reverberating chamber 8, thus slightlyreducing the eifect of the reverberating chamber 8 on the high frequencynotes; while, of course, the rather long horn It will add brilliancy tothese high frequency notes. Also, the sound released from the horn I8 isblended, at the top of the reverberating chamber 8, with the sound andoutput of two dynamic cone speakers, next to be mentioned.

Mounted on the under surface of the board 6, in which there are formedthe openings l1 and I8, are the two dynamic type cone speakers I1 and18.

At the right of the cabinet I (Fig. 1) there will be seen a small shelf9, on which is mounted an amplifier 20 with the lead wires 2| which areconnected with the dynamic speaker while from these lead wires 2| arethe further lead wires 22 connected with the dynamic speaker I8.

Likewise, to the left of the cabinet -I is a small shelf 23, on which ismounted the amplifier 24, with its lead wires 25 which are connected tothe driver type speaker l5.

Leading from the playing instrument, such as an electric organ, are thelead wires 26 that are in turn connected to the amplifiers 20 and 24.Thus the electrical impulses from the playing instrument (not shown) areamplified and passed through the dynamic cone speakers l1 and I8, andalso are amplified and pass through the dynamic driver type unit l5which has its horn IE, it will be remembered, mounted within thereverberating chamber 8 and which horn extends to nearly the top of thereverberating chamber 8.

Glancing at Fig. 5, for the moment, it will be noticed that the board 5directly over the apex ll] of the housing i has a plurality of openings2? with radiating spokes 28 and a central hub 29. Thus the sound thatpasses through the upper end of the reverberating chamber 8 will alsopass out of these openings 2'1.

Mounted in the hub 29 may be seen the ball bearing 30, so that a driveshaft 3| may be mounted therein, and the upper end of this shaft 3| issecured in the hub 32 of what I term a rotor sound deflector 33.

From the hub 32 radiate the spokes 34 and between which are the openings35, there also being the outside rim 35 to which the spokes lead, andthis rim 36 forms the periphery of the flector rotor sound deflector 33,which is notched on its outer surface as at 31, so that a belt 38 may bepassed around the same and extend to a drive wheel 33 which is securedon the end of a shaft 43 of a motor 4| which is secured as at 42 to theunder surface of the supporting board 5.

Securely fastened to the rim 35 of the rotor sound deflector 33 is anangular disposed metal hood 43 which is cut out across the face to forma mouth 44, which is only slightly less than the diameter of the rim 33,as may be seen in Figs. 1 and 3.

As will be noticed in Fig. 3, the hood 43 has a rim 45 around its baseso that it may be conveniently fastened to the rim 36 of the rotor sounddeflector 33, and I preferably put a rubber cushion 48 beneath the rim45 and on the upper surface of the rotor 33 to thus deaden any noisethat might be caused by the mechanical rotating of the wheel 39 or anymetallic sound that might be caused by the joining of the hood 43 withthe rotor 33.

Thus it will be seen that the sound passing through the upper end of thereverberating chamber 8 passes through the openings 27 in the board 5,and also between the openings 35, or in other words, between the spokes3d of the rotor sound deflector 33; and from these openings 35 the soundwill impinge against the inner surface of the metal hood 43 and beemitted from the mouth 44 of the rotor sound deflector 33 in a lateraldirection.

It will be understood that as the sound deflector 33 is rotated by themotor 4| the sound emanating from the reverberating chamber 8 isdeflected and projected in a lateral direction. Furthermore, a tremoloeffect is obtained, as if a person were listening at any one point aboutthe cabinet I, the sound will be the loudest when the opening 44 in thehood '43 of the sound deflector 33 is pointed directly towards him; andthe sound will then diminish as the opening recedes to its minimum at apoint directly opposite him. The sound will then increase as thedeopening 44 approaches him, until it reaches its maximum at the startof the cycle. Thus the sound tends to rise and fall at each revolutionof the sound deflector 33, thus creating a very smooth and even andpleasing tremolo effect.

Of course, the speed of rotation of the sound deflector 33 regulates thebeat or frequency of the tremolo effect; and this in turn is controlledby the speed of the motor 4| and the ratio of the pulley wheel 39 on themotor 4'| attached to the sides of the notched rim 35 of the sounddeflector 33.

As is well known, there is always a certain amount of sound that escapesfrom the back of a dynamic cone speaker, and so that the tremolo effectwill be added to any sound that is emitted from the back of the dynamicspeakers l1 and I8, I utilize a second rotor sound deflector 33'.

This deflector 33' is similar in construction to the rotor sounddeflector 33 with the exception that the periphery is not grooved as itis rotated by the shaft 3| which is also secured at its lower end as at41 to the hub 48 of this deflector 33'.

There is a similar metal hood 43' secured over this rotor sounddeflector 33'. Also, the openings 6 heretofore mentioned in the board 3are provided with spokes 4', so as to support the hub 49 in the board 3;and there are openings 35' in the rotor sound deflector 33' that areidentical with the openings 35 in the rotor sound deflector 33.

The bottom of the cabinet I is provided with a sound board50 in whichthere is a lattice or grille work so that the sound emanating from themouth 52 of the rotor sound deflector 33' will pass through the openings5| in the board 50.

Thus all the sound that emanates or passes through the upper end of thereverberating chamber 8, through the rotor sound deflector 33, will begiven a tremolo effect; and in the same manner, the sound that passesthrough the back of the dynamic speakers l1 and I8 will strike thebaflle board 3, then pass out of the openings 4, and through the hoodedsound deflector 33 and will also have the tremelo eifect similar to thatemanating from the upper rotor sound deflector 33.

I have found in actual practice that if the two sound deflectors 33 and33' are rotated at about 350 R. P. M. the tremolo effect is verypleasing.

It is also to be appreciated that by providing a hooded deflector 33 atthe top the sound is transmitted in a lateral direction and withoutincreasing the volume of the amplifiers the music can be heardthroughout a large'room in a complete circle of 360.

It might be mentioned that the tremolo effect is very pronounced, whichcan readily be ascertained by playing the organ (not shown) beforestarting the motor 4| to first let the sound simply pass through thereverberating chamber 8 and the deflectors 33 and 33' without rotatingthem; and then as soon as the motor 4| is started and the deflectors 33and 33 start to rotate, the great difference in tremolo can instantly benoted, while the fullness and the richness of the notes, or the timbre,seems to be much improved.

I have also found in actual practice that the tremolo effect is smoothand even at all the frequencies, that is, in the middle, the high, andthe low.

If just a small horn is revolved in a horizontal plane, it willfaithfully reproduce the high frequency and provide a tremolo, but hasno effect on the middle or bass frequencies; whereas, if just a dynamiccone type speaker is used with a revolving drum, then there is a drop inthe tremolo effect on the middle frequency range.

However, by using the various parts outlined and having two rotor sounddeflectors locked on the shaft so that they rotate in unison, thetremolo effect is heard over the entire range of audio-frequencies, andthe tremolo effect from the top of the cabinet is in perfect unison withthe tremolo effect from the bottom of the cabinet.

Again, by using the reverberating chamber 8, the notes from an electricorgan simulate those of the pipe organ tones; and the brilliancy of themusic seems to be greatly enhanced.

By using the two cone speakers and the driver type of unit and havingthe combined sounds pass through these two rotating sound deflectors, Ican provide a tremolo eifect that is always desirable in organ music,and I can simulate the music from a pipe organ.

It might be mentioned in passing that I have tried just bafliing thesound in the lower end of the cabinet, but the effect was far inferiorto using a second rotor sound deflector at the bottom of thereverberating chamber as above illustrated and described.

Finally, it will also be appreciated that these sound deflectors are notin a true sense a horn, but a means of breaking up the sound to give the'6 tremolo effect and to emit the soundin a full circle of of 360".

Many slight changes might be made withou in any way departing from thespirit and scope of the invention.

Having thus described my invention, what I claim is new and desire tosecure by Letters Patent is:

1. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal housing within the cabinet forming areverberating chamber, a dynamic cone speaker mounted in the lower endof the chamber, a dynamic driver type speaker also leading into saidreverberating chamher, a sound deflector rotor operably mounted at theupper end of the reverberating chamber, and an electric amplifyingcircuit for operating the speakers.

2. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal housing within the cabinet forming areverberating chamber, a dynamic cone speaker mounted in the lower endof the chamber, a dynamic speaker type speaker having a relatively longhorn extending within the reverberating chamber and to a point near thetop thereof, a rotary sound deflector operably mounted at the upper endof the reverberating chamber, and an electric amplifying circuit foroperating the speakers.

3. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal housing open at its opposite ends within thecabinet and forming a reverberating chamber, two dynamic cone speakersmounted in the lower end of the chamber, a dynamic driver type speakerhaving a relatively long narrow horn extending within the reverberatingchamber and to a point near the top thereof to blend the soundstherefrom with the sounds from the dynamic cone speakers, a rotary sounddeflector operably mounted over the upper end of the reverberatingchamber to deflect the sounds from the reverberating chamber in alateral direction, and an electric amplifying circuit for operating thesaid three speakers.

4. In a sound reproducing system for electric,

organs and the like, a tonal cabinet, a metal housing within the cabinetforming a reverberating chamber, a dynamic cone speaker mounted in thelower end of the chamber, a dynamic driver type speaker also leadinginto said reverberating chamber, a sound deflector operably mounted atthe upper end of the reverberating chamber, a second rotary sounddeflector mounted to the rear of said dynamic cone speaker and operatingin unison with said first mentioned sound deflector, and an electricamplifying circuit for operating the speakers.

5. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal housing within the cabinet forming a.reverberating chamber, two dynamic cone speakers mounted in the lowerend of the chamber, a dynamic driver type speaker having a relativelylong horn extending upward in the reverberating chamber and to a pointnear the top thereof, a rotary sound deflector operably mounted over theupper end of the reverberating chamber, a baffie board beneath the twodynamic cone speakers, a second rotary sound deflector mounted on saidbaille .board and operably connected with housing within the cabinetforming a reverberating chamber, speakers directing the sounds issuingtherefrom into the reverberating chamber, a metal shaft extendingthrough the reverberating chamber, sound deflectors connected to saidshaft, means for rotating said shaft and said sound deflectors, and anelectric amplifying circuit for operating said speakers.

mm a sound reproducing system for electric organs and the like, a tonalcabinet, a metal housing within the cabinet being larger at the basethen at its apex to form a reverberating chamber, dynamic cone speakersmounted in the lower .end of the chamber, a dynamic driver type speakerhaving a relatively long horn extending upward within the reverberatingchamber and to a point near the top thereof, a battle board mounteddirectly beneath the dynamic cone speakers, a rotary sound deflectormounted at the top of the housing and a similar sound deflector mountedon the under-surface of the bafile board, interconnecting means betweenthe said sound deflectors, means for rotating the sound deflectors inunison and an electric amplifying circuit for operating the saidspeakers.

8. In a sound reproducing system for electric org-ans and the like, atonal cabinet, a metal open-ended housing within the cabinet forming areverberating chamber, dynamic cone speakers mounted in the lower end ofthe chamber, a dynamic driver type speaker also leading into thereverberating chamber, a bafile board mounted directly beneath thedynamic cone speakers, said battle board having a central opening, arotary sound deflector mounted at the top of the housin and a similarsound deflector mounted over the opening in the battle board, each ofsaid sound deflectors having a metal angular-shaped hood with arelatively large mouth, means for operating the rotary sound deflectorsin unison, and an electric amplifying circuit for operating thespeakers.

9. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal open-ended housing within the cabinet forming areverberating chamber, speakers of different types for directing soundsinto the reverberating chamber, a baflle board beneath the said speakershaving a central opening therein, a sound deflector mounted at the upperend of the housing and a second sound deflector mounted across theopening in said baflle board, each of said sound deflectors including aspoked circular base and a metal hood extending at an angle to thehorizontal, the mouth of the hood being only slightly less than thediameter of the circular base, electric means for operating thespeakers, and electric means for rotating the sound deflectors.

10. In a sound reproducing system for electric organs and the like, atonal cabinet, a metal open-ended housing within the cabinet forming areverberating chamber, speakers of different types for directing soundsinto the reverberating chamber, a baflle board beneath the said speakershaving a central opening therein, a sound deflector mounted at the upperend of the housing and a second sound deflector mounted across theopening in said baille board, inter-connecting means between the twosaid sound deflectors, each of said sound deflectors including a spokedcircular base and a metal hood extending at an angle to the horizontal,the mouth of the hood being only slightly less than the diameter of thecircular base, electric means for operating the speakers and electricmeans for rotating the sound deflectors.

ORAS R. LAJVRENCE.

